Here's a post I made a while back that might help with age :
InCost of a link is basically a mapping of the LQI figure into a range of numbers from 1 to 7, lower numbers indicating better signal reception at the hub; whereas outCost numbers are indicative of reception at the remote end of the link (at the receiver of the repeater), derived from that repeater's measure of its own LQI (which isn't displayed).
